Q52 of 153 Page 148

In the adjoining figure, y = ?

x + y + 90 = 180 (sum of angles on a straight line)

x + y = 90 ………………….(i)

3x + 72 = 180 (sum of angles on a straight line)

3x = 108

x = 108/3 =36^O

Putting this value in eq (i), we get

x + y = 90

36 + y = 90

Y = 90 – 36 = 54^O

If the vertical angle of a triangle is 130°, then the angle between the bisectors of the base angles of the triangle is

The sides BC, BA and CA of ΔABC have been produced to D, E and F respectively, as shown in the given figure. Then, ∠B = ?

Each question consists of two statements, namely, Assertion (A) and Reason (R). Choose the correct option.

Assertion (A)	Reason (R)
If the two angles of a triangle measure 50° and 70°, then its third angle is 60°.	The sum of the angles of a triangle is 180°.

Each question consists of two statements, namely, Assertion (A) and Reason (R). Choose the correct option.

Assertion (A)	Reason (R)
If a ray stands on a line such that ∠ACD = ∠BCD, then ∠ACD = 90°.	If a ray stands on a line then ∠ACD + ∠BCD = 180°.